SiG 33 gun was installed on the chassis of tank Pz.Kpfw 38(t) by the firm VMM. The production of new tank hunter Sd.Kfz. 138/1 Ausf H Bison was started in February 1943. Its arms consist of 150mm SiG 33 gun. The thickness of front armor was equal to 25mm. In total 90 Ausf H Bison self-propelled guns were manufactured.